A yellowed plastic or fiberglass bathtub is never an attractive sight, either to the homeowners or guests using the facilities. Unfortunately, many effective cleaners for enamel bathtubs are often harsh and abrasive, which will damage your existing plastic tub. The good news is that a common household product can be used to eliminate the yellowing of your bathtub, making it shine brighter and whiter than before. Get rid of nasty yellow stains in your plastic bathtub using hydrogen peroxide.
Fill a spray bottle with 3-percent hydrogen peroxide, which is found in drugstores or convenience stores for a minimal price.
Move the shower curtain and any fabric items such as bath mats, towels and washcloths, into a safe location. Hydrogen peroxide whitens your tub, and it will also bleach fabric.
Remove any bathing or showering supplies such as shampoo, soap and shower caddies from your bathtub area.
Rinse the inside of the tub to get rid of any particles, hair or dirt. If there is any visible soap scum, scrub using a non-abrasive sponge with a standard soap scum remover formulated for plastic surfaces. Follow the instructions carefully.
Rinse the inside of the tub to remove any cleaner, if necessary. Spray the entire inside of the tub with the hydrogen peroxide. Let the solution soak for 10 to 15 minutes.
Wipe the inside of the tub with a wet, clean non-abrasive sponge. If more whitening is needed, repeat Steps 5 and 6 until the yellowing is completely removed.